Data Transmission Device, and Method and Computer Readable Medium Therefor

1. A data transmission device configured to connect with a plurality of terminal devices via a network, comprising: a data transmission unit configured to transmit data sequentially to the plurality of terminal devices based on a queue that stores destinations of each of the plurality of terminal devices; a determining unit configured to determine a transmission method for transmitting the data to each of the plurality of terminal devices; and a controller configured to, when the data transmission unit fails to transmit the data to a first terminal device of the plurality of terminal devices in a first transmission method, control the determining unit to determine a second transmission method for retrying to transmit the data to the first terminal device, and control the data transmission unit to retry transmitting the data to the first terminal device via the second transmission method after the data transmission unit tries to transmit the data to terminal devices to which the data has not been successfully transmitted among the plurality of terminal devices other than the first terminal device, wherein the data transmission device further comprises a queue updating unit configured to update the queue to add, behind a last destination stored in the queue, the destination of the first terminal device to which the data transmission unit fails to transmit the data in the first transmission method.

2. The data transmission device according to claim 1 , wherein the second transmission method is different from the first transmission method in at least one of a transmission protocol and a data transfer route.

3. The data transmission device according to claim 1 , wherein the controller is configured to, when the data transmission unit fails to transmit the data to the first terminal device in the first transmission method, control the data transmission unit to retry to transmit the data to the first terminal device in the first transmission method at least one time, and wherein the controller is configured to, when the retry to transmit the data to the first terminal device in the first transmission method fails repeatedly a predetermined number of times, control the determining unit to determine the second transmission method different from the first transmission method, and control the data transmission unit to retry to transmit the data to the first terminal device in the second transmission method.

4. The data transmission device according to claim 1 , further comprising a storage configured to store a plurality of transmission methods for each of the plurality of terminal devices in association with respective priorities of the transmission methods, wherein the determining unit is configured to select the second transmission method for the retry to transmit the data to the first terminal device from the plurality of transmission methods stored in the storage in descending order of the priorities.

5. The data transmission device according to claim 4 , wherein the first transmission method is a method that requires certification for establishing communication with a destination terminal device, and wherein the determining unit is configured to, when the data transmission unit fails to transmit the data to the first terminal device in the first transmission method due to a certification error, control the determining unit to determine a transmission method that does not require the certification as the second transmission method.

6. The data transmission device according to claim 4 , wherein the controller is configured to, when the data transmission unit fails to transmit the data to the first terminal device in the first transmission method due to capacity shortage of the first terminal device, control the transmission unit to retry to transmit the data to the first terminal device in the first transmission method after a predetermined time period has elapsed since the failure in the data transmission.

7. The data transmission device according to claim 3 , wherein the controller is configured to, when the data transmission unit fails to transmit the data to the first terminal device in the first transmission method due to capacity shortage of the first terminal device, control the transmission unit to retry to transmit the data to the first terminal device in the first transmission method after a predetermined time period has elapsed since the failure in the data transmission.

8. The data transmission device according to claim 4 , further comprising an updating unit configured to update a priority of a transmission method employed for successful data transmission to a highest priority.

9. The data transmission device according to claim 1 , wherein the updating unit is configured to update the queue to add, behind the last destination stored in the queue, the second transmission method along with the destination of the first terminal device to which the data transmission unit fails to transmit the data in the first transmission method.

10. The data transmission device according to claim 1 , further comprising a notifying unit configured to, after the data transmission unit completes tries to transmit the data to the plurality of terminal devices, notify a predetermined terminal device of a result of the tries to transmit the data to the plurality of terminal devices.

11. The data transmission device according to claim 1 , wherein the network is a Local Area Network (LAN).

12. A method for transmitting data sequentially to a plurality of terminal devices via a network, the method comprising the steps of: transmitting the data to a first terminal device of the plurality of terminal devices in a first transmission method based on a queue that stores destinations of each of the plurality of terminal devices; determining a second transmission method for retrying to transmit the data to the first terminal device when the transmitting the data to the first terminal device in the first transmission method fails; updating the queue to add, behind a last destination stored in the queue, the destination of the first terminal device to which the transmitting the data in the first transmission method fails; and retrying to transmit the data to the first terminal device via the second transmission method after trying to transmit the data to terminal devices to which the data has not been successfully transmitted among the plurality of terminal devices other than the first terminal device.

13. A computer readable medium storing computer-readable instructions therein that, when executed by a controller of a computer configured to connect with a plurality of terminal devices via a network instruct the controller to control the computer to perform the steps of: transmitting data to a first terminal device of the plurality of terminal devices in a first transmission method based on a queue that stores destinations of each of the plurality of terminal devices; determining a second transmission method for retrying to transmit the data to the first terminal device when the transmitting the data to the first terminal device in the first transmission method fails; updating the queue to add, behind a last destination stored in the queue, the destination of the first terminal device to which the transmitting the data in the first transmission method fails; and retrying to transmit the data to the first terminal device via the second transmission method after trying to transmit the data to terminal devices to which devices the data has not been successfully transmitted among the plurality of terminal devices other than the first terminal device.